Strictly speaking, Radish34, the first demo code that started the Baseline Protocol project in 2019, is not a reference implementation. It is a complete stack written as a proof of concept for a specific story around the use case of purchase orders and discount agreements. This work does not separate the implementation from a set of core, abstract interfaces. But it did allow the open source community to begin the abstraction and generalization process that resulted in the Baseline Protocol v0.1 (and subsequent) versions.